METHOD FOR HYDROFORMING HOLLOW PROFILE METAL WORKPIECES

摘要

A method for hydroforming hollow metal workpieces includes submerging the same in a reservoir of hydraulic fluid. A press is provided having a hydroforming station located within the reservoir and includes a forming cavity configured to receive the fluid filled workpiece and create a fluid cushion spaced between the outside of the workpiece and the inside of the forming cavity. Sealing mandrels supply high-pressure hydraulic fluid to the interior of the workpiece which hydroform the same to the shape of the final part. The outward flow of fluid from the fluid cushion space is controlled, along with the associated pressure, to maintain the fluid cushion at least until such time as the mandrel pushing step concludes, thereby alleviating friction and adhesion between the formed part and the forming cavity.